1. Field of the Invention
The present invention relates to spider assemblies for drum brakes and in particular to an improved spider assembly for a light weight drum brake comprising a stamped spider body and a removable, replaceable anchor pin member mountable thereto.
2. Description of the Prior Art
Drum brakes having a pair of generally arcuate brake shoes pivotally mounted at one end to an anchor structure and selectively actuatable at the other end thereof to pivot radially outwardly relative to the anchor structure to frictionally engage a brake drum are well known in the prior art. Usually, the brake shoes comprise an accurate table carrying the friction material and at least one radially inwardly extending rib or web. Typically, the pivotally mounted ends of the brake shoe webs are formed with either generally concave surfaces or generally annular aperatures which are pivotably supported by an anchor structure comprising a single anchor pin, or a pair of anchor pins, fixed to the brake spider assembly. A resilient retaining member, such as a coil tension spring, may be utilized to retain the brake shoes against the anchor number. Examples of such prior art drum brakes may be seen by reference to U.S. Pat. Nos. 2,710,076; 3,398,814; 3,507,369; 4,157,747 and 3,467,229, all of which are hereby incorporated by reference.
While these prior art devices are generally satisfactory and enjoy great commercial success, a problem has occasionally existed with the anchor pin, or pins, thereof. The anchor pins of the prior art devices, especially brakes having stamped spider bodies, were usually fixedly mounted to the brake support structure, usually referred to as the brake spider, as by a staked press fit. When the anchor pins occasionally became loose, dislodged and/or otherwise damaged, it was difficult to replace same, especially if a press and/or specialized fixtures were not readily available, and often a new spider assembly was required. In certain types of brakes, such as trailer axle brakes, wherein the spider is typically welded or otherwise none removably attached to an axle housing, this situation was particularly unsatisfactory.